Wednesday, 15 February 2017

International Radio Fair and World Radio Day

Hello All...
For last few years Outreach International used to organize a radio fair. This year too they organized "International Radio Fair 2017" at Bhubaneswar, Odisha. Besides other participants, Amateur Radio Society of Odisha(ARSO) participated in the fair too. 
Main Attractions:
The main attractions of this fair was HAM radio, vintage radio collection and radio related stamp collection.

International Radio Fair 2017 Bhubaneswar, Odisha.

The Sand Art for World Radio Day in the venue

Vintage Radio collection:
 Mr. Ghanasyam collected several radios Most of them are vintage tube radios. Though they are non functional but for a museum it is very nice to see radios from my Grand fathers time. Around 500 to 600 radios were on display.
Mr. Ghanashyam in his 80s now a radio lover, I would say Radio Crazy man.



Vintage Radio Stall from a distance.

Few Radios with close-ups


His collection includes several radios from Philips, Murphy, Bush and HMV to name a few...

Radio Philatelist:
The other attraction is Philatelist Mr. Ashok Kumar Tiwari. his collection includes Radio inventors/researcher, development of radio, broadcast history, Emergency Communication and HAM radio. A very nice and exhaustive collection.

Alexander Popov
J.C Bose
G.Marconi 

HAM radio related...
I could not put all the pictures of his collections, its huge...

Last but not the end... The HAM radio stalls.
In this category ARSO Bhubaneswar and ARCCS from Kolkata put up their stalls. Evan they have made a special call-sign for this Event(AT0IRF). In ARCCS stall, they have displayed and try to promote ON-AIR and how to reach out more people. On the other hand ARSO team focused on HAM radio Homebrew and Radio concepts.
VU2PQS(sitting) VU3XUS and VU2AOR

VU2PQS describing About HAM radio


VU2ABG from Surat came to meet ARSO team.
Concluding remarks:
Though it was a very nice initiative, participation should have been more. Though it is organized jointly by UNESCO no International participation seen. hope coming year these shortcomings are fulfilled.

Tuesday, 10 January 2017

Somuch of water flowed to ocean during my absence

First thing first....
Wish Everybody 
a Happy and Prosperous 
New Year ahead.
Well I was in a hibernation 😄😄😄
During this period I have setup my HAM Radio Station. Equipped with VHF(QYT KT 8900) And HF BITX 40m from VU2ESE Farhan. My antenna is a Inverted V for HF and 0db GP for VHF both are mounted on a 35 feet Bamboo mast.
As VHF is factory built till now it functions well. I have successfully communicated 30 Kilometer air distance on VHF(10Watts and 20 Watts). Further reach is possible but our club members are within this perimeter only.

BITX 40m as it is obtained from VU2ESE is good but only problem is on-board VFO, which drifts with time and while TXing. But I got 58 report from our club members within 30 kilometers. I was received by VU3SUY and VU2PLL but due to drifting VFO my calls were rejected 😀.

For your eyes thirst I am putting some pictures.

UnBoxing QYT KT 8900
BITX and QYT KT 8900 stacked.
My Antenna mast.
The VHF setup is courtesy VU2BPJ. I am very much thankful to him.
The HF setup is assembled and Tested by VU2AOR. I Express my gratitude for his help and advice.
The final boxing is done by my Electronics Guru BUDHANA( SWL Tushar Kanti Mishra).

I also express my sincere thanks toVU2AOR,VU2BPJ, VU2PQS,VU2FRD, VU2DKD and VU2CSF for coordinating testing of my setup.

BACKLOG:
First of all I beg apology for not posting the Compiler Blog in time.
The project is semi complete and working in a minimal sense. I will post the code in a future blog shortly.


Tuesday, 9 August 2016

My Experiment with Compiler Writing. Part-1

Introduction

Well, I have written a small OS kernel(NanoOS) earlier(2008-2010). It was written in C++ and assembly language for Self learning as well as for Fellow colleagues at Redhat, Pune. But never tried a compiler or interpreter, as it was never needed for my Job.

The need

Recently for a small project I had to write a small parser. It is not a language parser though.  It was written for a parsing a logfile of an application. Even it was designed to detect wrong sequence in that application. Well forget about the application. After that project is complete I thought to write a small Interpreter or Compiler for a very small language. As a first thought It came to me that I should write a Compiler for BASIC(Beginners' All purpose Symbolic Instruction Code) but implementing a full blown BASIC compiler is a big task for me(I sincerely believe I am not that intelligent to write a full blown compiler single handedly). So in my so-called Compiler a very very small subset of BASIC language will be implemented, as it was meant for self training and example for who ever wants to study this subject practically.

My approach

I prefer practical way to learn. So i will try to lay down fragments of code in sequence. So that any one can follow and understand.
  1. We will be using C or C++ 
  2. We will start with a very basic tokenizer
  3. Modify the code to have a parser
  4. Code generator.
Why I choose C or C++ is, I write code more easily in these 2 languages. Any other language can be used. Even BASIC can be used to write a BASIC compiler.
But it needs through understanding of the language.

I deliberately avoided Gramars and all those Compiler jargon. If those things are needed then please pickup a Compiler writing book and read. If you have read such a book then you may find this article informative on implementation.

Keep in mind "This is not a tutorial for Compiler construction courses" or class assignment. Secondly Please Don't Expect it to be of any practical use. This is just for my personal pleasure and to share my pleasure with others.

In next instalment I will start with lexing/parsing code.

Thanks
DE VU3VFU

Saturday, 6 August 2016

A 30 years Dream

Today I got my HAM license. My call sign is VU3VFU( Viktor Uniform number 3 Viktor Foxtrot Uniform).

It was 1986 june. My Matric Exam(10th Board exam) was over. So no study pressure no mathematics no algebra no geometry no trigonometry... Initially it was enjoying but after 2 weeks it was horribly boring. While I was roaming in the market I saw EFY(Electronics For You). Got tempted and bought it. Those days it was costing Rs.5/- yes Five Rupees. I found it interesting but somany topics are over my head ( You know What I mean Hi Hi Hi).
In that issue they have published about HAM radio. when I read it I was thrilled. Can I really keep a Transmitter at home??? intrigued me.

I read that article repeatedly and convinced yes it is possible to have transmitters at home. Next is gathering information. Those days there were no internet, no mobile phone nothing. So ultimate part is going to electronics department and asking them. But I never find any answer from them.

Fortunately there was a Marine Radio Communication training institute in my college (Ravenshaw college).I  approached the chief instructor Mr.Choudhury. He gave me a good and convincing answer. I collected monitoring station's address in Gopalpur,Sarkarpul, Chabis praganas,WB. Wrote mail but they never gave inspiring or detailed procedure. Next my research found "ABC of Amateur Radio". I read that from begin to end.

Then time flew by and I joined Engineering college(UCE Burla.) in Civil Engineering. My interest gone dormant. But some fine day my younger brother(now K14DDY) informed me there are few hams at Sambalpur. I tried to meet them but unfortunately i could not. Then Course work pressure, then after completion JOB hunt from during 1993... I could not look towards HAM radio.

Then comes 2011. I came back to Odisha and Got to know about VU3PLP( now VU2FRD) called him up and his assurance kindled new hope in me and gradually we formed an association ARSO(Amateur Radio Society Odisha). Arranged Exam and Now we have 18 more HAMs in odisha...

This is my story it may not inpire you or not interest you, but I felt I should share this 30years of wait.
Any ways please share your story and comments.

Thanks 
de VU3VFU.

Saturday, 5 March 2016

My Experience with GP-5/SSB

Countycomm's GP-5/SSB is the prime radio for me now. Earlier I used RTL SDR and Kchibo.

Kchibo is not for HAM use. It is suitable for Broadcast(MW/SW/FM) listening. Where as RTL SDR is good for 5MHz to 1.7 GHz. I used it for BC,HAM band in 40m and 2m reception. 20m reception using modified driver under linux was not possible( I don't know Windows performance though).

After I got this GP-5/SSB receiver, my evening time pass is to listen to HAM QSOs on 20m mostly and sometimes on 40m too. This radio is a cute radio as you might have seen from my previous write-up or elsewhere. My friends here are envious about its performance and size.
With this GP-5 SSB I have received stations as far as Australia, Siberia, Srilanka, Oman and my latest reception of Netherlands (PD9Z). So also i have received local (VU) stations from Mangalore,Bangalore, Chennai, Vishaka Pattanam, Kolkata, Berhampore(Murshidabad), Patna, Nagpur, Kolhapur, Ahmedabad, Sambalpur, Bhubaneswar, Bramhapur and Delhi.

QRP and homebrew stations VU3JOJ from Murshidabad, VU3PLP from Bhubaneswar are my regular favourite.
QRO stations such as VU2DPI, VU2YK and VU2KD are received like broad cast station clarity.

To emphasize the sensitivity of this receiver, i can say I have received a portable mobile HF station(VK6HCF) from VK land.

Power consumption is higher ( As i observed). In the beginning  I used AA alkaline cells made by Panasonic India (Golden colour). Those cells are drained out in 3 to 4 days if I use for 2 hours in the evening and one hour in the morning. To eliminate the battery issue i started using 2100mAh NIMH cells. The same thing happened as I have to recharge the cells every 3 to 4 days. I consulted the manual. There it says "if NIMH cells are used then the set must be set for NIMH cells". I changed the setting to my surprise after even 7 days cells are showing full power and there is no issues.

Bottom line:
Cute small Radio for radio lovers.
 

Wednesday, 6 January 2016

CountyComm GP-5/SSB receiver.

Yesterday I received a GP-5/SSB receiver from CountyComm with some other goodies as a prize for "Virtual Radio Challenge IV" at Swling.com. After a long time I am receiving a prize.. Hi Hi Hi...

This radio is not for those who listens music on FM bands. It is for the Radio Fans and Radio Enthusiasts. Besides normal AM and FM demodulation it has SSB capability too.

Tuning range 550KHz -1710KHz can be changed to 150KHz-1620KHz
SW tuning is 1711KHz to 29999KHz continuous. This is a bit problem as one has
to rotate the wheel ... But to ease these there is preset BC bands and HAM bands too. Simultaneously there is scanning feature and Manual Memory feature for station surfing. 
FM tuning 76MHz-108MHz or 87MHz-108MHz

FM audio quality is very good
AM audio quality is very good
SW audio is good but noise (though SW bands are noisy except night time)
SSB is good One has to change BFO shift for clarity and lesser noise.

Overall it is a Good to have radio.

Friday, 25 December 2015

ARSO info and my Winning of Virtual radio Challenge IV

Greetings for the Festive Season
Merry Christmas to all.

ARSO:
For the past few months I was busy. During these days some enthusiast HAMs and SWLs of Odisha,India came closer and unanimously decided to meet every Sunday afternoon. I am one of them.

As days passed few veteran HAMs suggested to start an association which will bring all the active inactive HAMs and SWLs Radio enthusiasts together. currently this association has a name "Amateur Radio Society of Odisha (ARSO)".

Recently ARSO Organised ASOL exam on 20th December 2015. Good number of candidates shown interest in appearing the exam. to be precise 21 candidates have filled up the form but 20 candidates could manage to come to the exam venue on specified date and time. out of these 20 candidates 12 candidates appeared for Restricted grade and 8 candidates for General grade.

ARSO has conducted extensive classes for aspirants at ARSO office for exam preparation. ARSO been instrumental for Theory(Technical and Procedure) and also for Morse practice.  I am thankful to ARSO to organize the Exam at Bhubaneswar, Odisha.

The exam was conducted at OMC Auditorium, bhubaneswar. Examiner Mr. Panja from WPC conducted the Exam with supervision of Mr. Mallik, the Monitoring Officer stationed at Bhubaneswar. Senior HAMs OM Dilip Padhi(VU2DPI), OM Sameer Ranjan Panda (VU2AOR),  OM Priti Ranjan Mekap (VU3UFX), OM Rajesh Kumar(VU3PLP) and OM Gurudutta Panda(VU3GDP) encouraged the aspirants. At the end ARSO member Mr. Pankaj Bag sponsored a grand lunch to all who are present.

In future ARSO has promised to conduct more such events. Thanks ARSO for your effort.

SWLing:
In the mean time I also have participated in a contest organised by Thomas of Swling post. Besides his Nice informative reviews on radio related subjects, he also conducts some interesting challenges. Recently he posted such a challenge, Virtual Radio challenge IV
The good news is that I am runner-up in this event and Mehdi's entry was the winner. For details please read the result page.